1. Field of the Invention
The present invention relates to a light-guiding plate, and in particular to a method for manufacturing a light-guiding plate having a light-condensing effect by changing the traveling path of the light.
2. Description of Prior Art
With the progress and development of technology, portable electronic products such as mobile phone, personal digital assistant have become necessary information products for modern people. These electronic products are each provided with a key structure by which a user can input information or perform individual functions of the electronic product.
In order to allow the user to see the position and function of the key without the illumination of a light source, the key structure of the electronic product is provided with a back light source. The light generated by the back light source can allow the user to clearly see the position of each key and the pattern and numeral on the surface of the key without the illumination of the light source.
The back light source within the general key structure is a light-guiding plate. After the light-emitting element within the electronic product is lighted up, the light is introduced via the front end of the light-guiding plate and is projected onto the bottom of each key via the light-guiding plate, thereby to display the numeral and pattern of the surface of the key. In this way, the user may not erroneously press the wrong key even without the illumination of a light source. Since the light is introduced into the rear end of the light-guiding plate from the front end thereof, the intensity of the light will be gradually reduced, so that the brightness of the numeral and pattern displayed on the surface of the corresponding key on the rear end of the light-guiding plate is insufficient. Therefore, in order to make the light source on the light-guiding plate more uniform, a plurality of light-emitting elements and a light-refracting plate are additionally provided in the periphery of the light-guiding plate, thereby to uniform the light source on the light-guiding plate. This will cause the increase in the amount of electricity consumed by the electronic products and the cost accordingly.